Supersonic Drag Reduction with Repetitive Laser Pulses Through a Blunt Body

Abstract

A drag over a flat-nosed cylinder with repetitive laser pulse irradiations ahead of it were experimentally measured in a Mach-1.92, in-draft wind tunnel. Laser pulses were focused using a plane-convex lens fabricated on the nose of the cylinder at a repetition frequency of up to 10 kHz and power of 70 W at a maximum. The drag was measured using a low-friction piston which was backed by a load cell in a cavity at a controlled pressure. Under the experimentally available operation conditions, an up-to-3 % drag reduction and an efficiency of energy deposition of about 10 were obtained. Mechanisms of the drag reduction are analyzed based on experimental flow visualization and numerical simulation.